Beware These 3 Nutrition Dogmas

Nutrition dogmas are surprisingly common, with beliefs and presumptions too often driving conclusions, rather than good evidence. Here are three to beware.

Low Fat. Advice to adhere to a low-fat diet became almost universal in the 80s, continuing through the turn of the millennium. This strategy was enshrined in policy through nutritional guidelines, despite limited empiric support for long-term benefits. Beginning with faddish popularity of the Atkins diet in 2003, researchers began to dispute the wisdom of across-the-board recommendations for a low-fat strategy as the primary approach to weight management. Debates are ongoing about the merits of reduced fat dairy products and about the strength of data suggesting that fat consumption is a cause of heart disease.

Low Carb. Diets that emphasize restricting carbohydrates and sugars, such as Atkins, have been the beneficiary of waning confidence in low-fat dietary advice. Short-term studies continue to appear, suggesting a potential advantage for low-carb over low-fat diets. Headlines from one such study this week proclaimed, “Low-carb Diet Beats Low-fat Diet for Reducing Inflammation.” But careful experts warn against sweeping generalizations. Longer-term studies, such as the POUNDS LOST study, have found that “in most overweight people, a low intake of carbohydrate is not sustainable.” In fact, this study, like others, suggests that the most important factor for dietary interventions is long-term adherence. In other words, the best dietary strategy is one you can follow for the long term.

Artificial Sweeteners. Activists with a conviction that artificial sweeteners must be unhealthy promote two messages to support their dogma. One message track involves unsupported claims to suggest that these sweeteners are inherently toxic. Though a very few people are sensitive to aspartame, for example, no evidence exists to suggest that artificial sweeteners are unsafe. The other message track, also unsupported by real evidence, is that consuming foods sweetened with non-nutritive sweeteners will lead to a craving for sugary foods. Multiple rigorous evidence reviews have concluded that swapping non-nutritive sweeteners for sugar is a reasonable strategy to cut calories from your diet.

Click here to read the POUNDS LOST study, here to read the findings of a recent meta-analysis of the effects of low-calorie sweeteners on body weight, and here to read a bit more about balanced (or not) reporting on low-calorie sweeteners.